.content{
	width:720px;
	border:1px solid #000;
	border-radius:5px;
	text-align:center;
	margin:0 auto;
	
}
.item{
	width: 100px;
	height: 100px;
	border-radius: 5px;
	background-color:#009688;
	text-align: center;
	line-height: 100px;
	margin: 10px 10px;
	float: left;
}
.item-red{
	width: 100px;
	height: 100px;
	border-radius: 5px;
	background-color:#FF5722;
	text-align: center;
	line-height: 100px;
	margin: 10px 10px;
	float: left;
}

.clearfix::after{
	content:'';
	clear:both;
	display:block;
}